Feature Request

Hello,

urfave/cli (https://github.com/urfave/cli) is a fairly popular go cli toolkit.
It provides the ability to create a hierarchy of commands and attach flags reading to those commands.

In UNIX, it's often popular to use flags to pass (enforce) configurations via flags. This can be useful to avoid the need of a config file or simply to bypass a defaults, file or env configuration.

I see that there is already a PR to support urfave/cli/v2, however v3 is on the verge of being released and as such I think it would be great if we could provide support for both versions, hence this feature request.

I will gladly create the provider for v3 if @knadh is okay with this feature being added.